This paper presents a comparative review of arsenite (As(III)), arsenate (As(V)), and fluoride (F − ) for a better understanding of the conditions and factors during their adsorption with focus on (i) the isotherm adsorption models, (ii) effects of pH, (iii) effects of ionic strength, and (iv) effects of coexisting substances such as anions, cations, and natural organics matter. It provides an indepth analysis of various methods of arsenite (As(III)), arsenate (As(V)), and fluoride (F − ) removal by adsorption and the anions' characteristics during the adsorption process. The surface area of the adsorbents does not contribute to the adsorption capacity of these anions but rather a combination of other physical and chemical properties. The adsorption capacity for the anions depends on the combination of all the factors: pH, ionic strength, coexisting substances, pore volume and particles size, surface modification, pretreatment of the adsorbents, and so forth. Extreme higher adsorption capacity can be obtained by the modification of the adsorbents. In general, pH has a greater influence on adsorption capacity at large, since it affects the ionic strength, coexisting anions such as bicarbonate, sulfate, and silica, the surface charges of the adsorbents, and the ionic species which can be present in the solution.

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The ineffective management of household solid waste (HSW) in most developing cities in Africa including Monrovia has become a major issue threatening the environment and public health. In response to these waste challenges, developed countries have embarked upon major environmental reforms, and have made advances in best practices and sustainable management of their Municipal Solid Waste (MSW). However, in most developing countries like Liberia, such environmental reforms have not been initiated and therefore the situation has become compounded; this is due to several factors impeding the development of a sustainable municipal solid waste system. This study, therefore, aims to critically analyze the influencing factors of solid waste management; the characteristics of household waste and suggest management solutions for effective and sustainable management.<br/> Results from the analysis of data, using The Ordinary Least Square Regression (OLS) method estimates the average household waste per capita generation as 0.76kg/capita/day. Regarding the composition of the waste stream, the results show that 67% of the waste sampled from Monrovia is biodegradable and mostly comprised of high wet weight and high moisture content kitchen waste. On the other hand, the remaining percentage is mostly non-degradable but recyclable materials such as glass ceramics and metals. This suggests that due to the high moisture content in the waste, samples are suitable for composting and other mechanical and biological management options. Using the stratified sampling method, 300 households were chosen. Multiple regressions were conducted to determine the relationship between waste generation and socio-economic factors and these showed that the effect of income, household size and the environmental concern on HSW generation is statistically significant at a 1% significance. However, further findings revealed a negative relationship between income and HSW generation at a 1% level of significance. These findings provide new insight regarding the role of socio-economic characteristics affecting the generation of household waste in Monrovia.

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Phthalates are typical air pollutants in vehicular environment since numerous synthetic materials that might contain phthalates are widely used to fabricate vehicle interiors (e.g., seat cushions, floor mats and dashboards). Hitherto, the importance of phthalate pollution in vehicular environment is not well‐recognized because people spend only a small portion (around 8%) of their time in vehicles. In this study, the mass fractions of six phthalates in nine materials commonly used in Chinese vehicles (floor mats and seat cushions) were measured. Two phthalates, di‐n‐butyl phthalate (DnBP) and di‐2‐ethylhexyl phthalate (DEHP), were identified in most materials (the other phthalates were not detected). The emission characteristics of DnBP and DEHP from these materials were further investigated. The measured emission parameters were used as input for a mass‐transfer model to estimate DnBP and DEHP concentrations in cabin air. Finally, the ratios between human exposures (via inhalation and dermal absorption from the gas phase) in vehicular environment and the total exposures in typical indoor environments (e.g., residences and offices) were estimated to be up to 110% and 20% for DnBP and DEHP, respectively. Based on these results, the vehicular environment might be a considerable site for human exposure to airborne phthalates.